1. Field of the Invention
The present invention relates to a shower apparatus that discharges aerated bubbly water.
2. Description of Related Art
Known examples of water discharge apparatuses include one which discharges bubbly water by aerating water using a so-called ejector effect. When the water discharge apparatus of this type is configured as a shower apparatus which distributes water flowing into the apparatus to multiple nozzle holes and discharges it therefrom, in order to aerate the shower stream to be discharged, the water flowing into the apparatus is aerated before being distributed to each nozzle hole.
An example of such a shower apparatus is proposed in Japanese Unexamined Patent Publication (Translation of International Application) No. JP2006-509629 T (hereinafter referred to as Patent Document 1). The shower apparatus described in Patent Document 1 comprises a plurality of nozzle holes provided in the front face of a disk-shaped housing shell, and is configured to distribute water flowing into the apparatus through the center of the rear face of the housing shell to the plurality of nozzle holes and discharge it from the nozzle holes. The shower apparatus is also configured to produce bubbly water by aerating water when the water has flowed into the housing shell and distribute the obtained bubbly water to the plurality of nozzle holes which are formed such that the nozzle holes are distributed over the entire front face of the disk-shaped housing shell. In the shower apparatus, a turbulence generation/expansion unit is placed in a traveling direction of the bubbly water, causing the bubbly water to collide with the turbulence generation/expansion unit to change direction and thereby spreading the bubbly water over the entire front face of the housing shell.
Another example of such a shower apparatus is proposed in Japanese Patent No. 3747323 (hereinafter referred to as Patent Document 2). In the shower apparatus described in Patent Document 2, when a faucet such as a hot and cold mixer tap is opened, water is supplied from a hose and allowed to pass through an orifice member. When the water passes through the orifice member, a decompression chamber which is provided downstream of the orifice member is maintained under reduced pressure so that air is sucked through an inner suction port, which is an opening formed in the decompression chamber, and mixed with the water. The shower apparatus described in Patent Document 2 produces bubbly water in this manner and discharges the bubbly water through a plurality of nozzle holes provided in a shower head. In this shower apparatus, the produced bubbly water proceeds to the nozzle holes by changing direction by hitting a threaded member in a partitioned pipe disposed downstream of the decompression chamber and also hitting inner walls of the shower head disposed further downstream.
Furthermore, as a shower apparatus that discharges bubbly water, Japanese Unexamined Patent Publication No. JP2008-237601 A (hereinafter referred to as Patent Document 3) proposes a shower apparatus which comprises a fine-bubble generator equipped with a gas mixing unit for mixing gas into a water supply line through which shower water flows, the fine-bubble generator being configured to break up the gas mixed into the shower water by the gas mixing unit into fine bubbles so that the shower water to be discharged from a shower water discharge unit disposed at an outlet of the water supply line contains fine bubbles with bubble diameters of 0.1 to 1000 μm. The gas mixing unit is provided with a gas mixing rate control means for controlling the mixing rate of gas in the shower water, and a gas flow control valve, which is a solenoid valve serving as the gas mixing rate control means, is installed in a gas supply channel. The gas flow control valve is connected to a control unit that controls the operation of the shower apparatus so that the degree of opening of the valve is controlled by the control unit. Control of the opening of the gas flow control valve results in control of the channel diameter of the gas supply channel and thereby makes the flow rate of gas flowing through the gas supply channel variable.
The shower apparatus described in Patent Document 2 is intended to achieve a sensation of water hitting the user intermittently, as can be seen from the description in paragraph 0015 of the document. It is considered that the term “intermittently” means that the user can experience both strong and weak showers, which vary intermittently, by being hit by finely divided water droplets of non-uniform sizes, in which large-sized water droplets give the user a sensation of having a strong shower stream and small-sized water droplets give the user a sensation of having a weak shower stream. According to substantive studies conducted by the present inventors, it is presumed that immediately after the bubbly water is produced, air is mixed into the bubbly water substantially uniformly; whereas, when the bubbly water reaches the nozzle holes, the bubble diameters are non-uniform since the bubbles collide with each other as the produced bubbly water changes direction by hitting the threaded member or the inner walls of the shower head. When such bubbly water is discharged from the nozzle holes, it turns into water droplets of non-uniform sizes, and it is considered that the sensation described above can be achieved by directing such water droplets at the user.
Although Patent Document 1 does not have descriptions regarding the properties of the bubbly water discharged from the shower apparatus described in Patent Document 1, it is presumed that the shower apparatus supplies bubbly water with non-uniform bubble diameters to the nozzle holes to discharge it therefrom, thereby producing water droplets of non-uniform sizes and directing them at the user, as in the case of the shower apparatus described in Patent Document 2. Since the shower apparatus described in Patent Document 1 is provided with the turbulence generation/expansion unit arranged in the traveling direction of the bubbly water, to cause the bubbly water to change direction by colliding with the turbulence generation/expansion unit, it can be considered that similar non-uniform bubble growth also takes place in the shower apparatus described in Patent Document 1 and that the resulting water droplets of non-uniform sizes are directed at the user. Since both the shower apparatus described in Patent Document 1 and the shower apparatus described in Patent Document 2 give the user water droplets of non-uniform sizes which are formed from bubbly water containing non-uniform bubbles, they produce only a small difference between the strong and weak shower streams, and a sufficient stimulus sensation is thus not available.
On the other hand, in the shower apparatus described in Patent Document 3, the gas flow control valve, being the solenoid valve serving as the gas mixing rate control means, is installed in the gas supply channel, and the gas mixing rate control means allows intentional control of the bubble content; however, it becomes necessary to have the solenoid valve acting as the gas flow control valve. In other words, although the shower apparatus described in Patent Document 3 may be able to discharge bubbly water with a stimulus sensation, a means of physically operating a structure, such as a solenoid valve, is required, resulting in a water discharge apparatus which runs counter to size and cost reductions.
Under these circumstances, the present inventors conceived of providing a shower apparatus capable of providing a shower stream with a voluminous feel even when discharging a small volume of water, and also with a comfortable stimulus sensation arising from a large change in the instantaneous flow rate of the shower stream, and which also contributes to size and cost reductions. The above-described conventional techniques, which give the user a feeling of being hit by non-uniformly-sized water droplets, do not provide a shower stream with both a voluminous feel and a comfortable stimulus sensation such that the instantaneous flow rate of the shower stream is greatly changed. Further, the conventional techniques are not able to achieve size and cost reductions while providing a shower stream with both a voluminous feel and a comfortable stimulus sensation such that the instantaneous flow rate of the discharged water is greatly changed.